West Ham boss Slaven Bilic is well aware of the potential for a slip-up as his side chase Champions League qualification.

The Hammers are two points behind fourth-placed Manchester City and three adrift of Arsenal with nine Barclays Premier League games to play, beginning at Chelsea on Saturday.

"Our aim is to continue to play like this and pick up points and then hopefully it's going to take us high," Bilic said.

"I don't know how many (points) you need to get in the Europa League or the Champions League or whatever.

"I don't know. I'm not using that kind of maths. All I know about England is that you have to reach 40 points to stay up.

"It's just game by game and so far that kind of thinking has put us in a very good situation and, in my opinion, it is the only way that any club should think.

"You can't go and play Chelsea and then expect three points against whoever. It doesn't work like that, because in any league, especially here, there are no guarantees.

"We are totally focused on the possibility of three points (at Stamford Bridge)."

Bilic, who confirmed West Ham's interest in signing Borussia Monchengladbach midfielder Havard Nordtveit on a free transfer, says the club hope to tie up a permanent move for Manuel Lanzini after the Argentinian impressed on loan.

"Lanzini is a clear situation from the start," Bilic added.

"He came on loan from Al Jazira and we had an option and the contract is there so he's our player.

"He's happy here and we're of course happy with him and we want him in the club for a long, long time. My staff decided long ago that we want to activate that option."

Captain Mark Noble missed out on the England squad on Thursday, while another Hammers player has turned down Jamaica in order to fulfil his dream of playing for England.

Michail Antonio, who has impressed since joining from Nottingham Forest last September, told BBC Sport: "Jamaica called but if I keep doing what I'm doing hopefully I can get an England call."

Defenders James Tomkins (calf) and James Collins (hamstring) are still out for the Hammers.

Tomkins is to resume training this week and both are expected to be back after the forthcoming international break.